Packaging compressible materials



De 15, 1970 LUNDBER ET AL 3,546,828

PACKAGING COMPRESS IBLE MATERIALS Filed Oct. 25, 1967 4 Sheets-Sheet 1 INVENTO G.KLUN E D.E. PER BY ATTORNEYS Dec. 15, 1970 LUNDBERG ETAL 3,546,828

PACKAGING GOMPRESSIBLE MATERIALS Filed Oct. 25, 1967 4 Sheets-Sheet 2 FIG. 2

INVENTORS G.K.LLJNDBERG D.E.PERRY ATTORNEYS 1970 G. K. LUNDBERG ET AL 3,546,82

PACKAGING COMPRESSIBLE MATERIALS 4 Sheets-Sheet 3 Filed Oct. 25, 1967 INVENTORS GK. LUNDBERG mm No i PHMHIIrIIF' i mm Mn A TTORNEVS Dec. 15, 1970 LUNDBERG ETAL 3,546,828

PACKAGING GOMPRESSIBLE MATERIALS 4 Sheets-Sheet 4 Filed Oct. 25, 1967 INVENTORS GK. LUNDB ERG D. E. PERRY A TTORNEVS United States Patent 3,546,828 Patented Dec. 15, 1970 lice US. Cl. 53-24 7 Claims ABSTRACT OF THE DISCLOSURE A resilient compressible material, such as rock wool, is inserted in a longitudinally folded thermoplastic film or between two sheets of film and fed into an apparatus comprising two parallel coacting belts, a side sealing means and an end sealing means. The open sides of the package are sealed as the package is conveyed and compressed between the belts; when all of the material is between the belts, the air in the package is substantially displaced and the trailing end of the film is hermetically sealed to form a package containing compressed material. This compressed material expands to original size when the package is punctured or opened to the atmosphere.

This invention relates to packaging resilient compressible material. In one aspect the invention relates to a method of packaging. In another aspect the invention relates to an apparatus for packaging compressible material. In another aspect the invention relates to a package of compressed material which is punctured to allow the material to assume its expanded shape.

In packaging certain resilient compressible materials such as insulation batts of rock wool or glass wool, it is desirable to compress the material to reduce the volume thereof. Shipment of the compressed volume results in lower transportation costs and when removed from the carton or package the resilient material assumes its original shape.

The invention provides an apparatus and method whereby compressible materials are simultaneously compressed and packaged in thermoplastic film at high speed. The volume of the package produced is large enough to allow the compressed material to expand to its uncompressed shape inside the plastic bag when the bag is punctured. The package has the additional advantages of providing convenience in handling and of facilitating installation of materials such as rock wool batts, The rock wool can be installed in its compressed package and the package punctured or opened to the atmosphere to allow the material to expand.

Accordingly it is an object of the invention to provide an improved apparatus for simultaneously compressing and packaging resilient compressible materials.

Another object of the invention is to reduce the cost of packaging and transporting compressible materials.

Another object of the invention is to provide a package which when sealed retains a compressed material in its compressed state and which when punctured permits the material to expand.

These and other objects of the invention will be apparent to one skilled in the art upon consideration of the following disclosure, drawings and appended claims.

FIG. 1 is an isometric view partially in section of one embodiment of the apparatus of the invention.

FIG. 2 is a side elevation view partially in section of the apparatus illustrated in FIG. 1.

FIG. 3 is a front view of another embodiment of the apparatus of the invention.

FIG. 4 is an isometric view giving details of a side sealing means.

FIG. 5 depicts the package of the invention in its evacuated and partially collapsed state.

According to the invention, there is provided an apparatus for packaging lengths of a resilient compressible material in a thermoplastic film comprising in combination: a frame; a lower conveyor means mounted on the frame; an upper conveyor means mounted on the frame parallel to and above the lower conveyor means to form a compressing and conveying assembly which has a feed end and a discharge end, the assembly being at least as long and as wide as the length of material being packaged; drive means to drive the conveyor means in the same direction at the same speed; end sealing means mounted on the frame for intermittent vertical movement into the path of the material being fed to the compressing and conveying assembly to seal the thermoplastic film transverse to the direction of travel; side sealing means mounted adjacent to the compressing and conveying assembly to seal the thermoplastic material extending beyond the sides of the assembly. The lower conveyor means and upper conveyor means are spaced apart a vertical distance equal to the thickness to which it is desired to compress the material being packaged.

In one embodiment of the apparatus, side sealing means are provided on either side of the compressing and conveying assembly to seal and package a length of compressible material which is sandwiched between two sheets of thermoplastic film. In another embodiment of the invention, the material is placed in a longitudinally folded film and a single side sealing means is employed to seal the open edge.

Further in accordance with the invention, there is provided a partially evacuated and collapsed air impervious film package of compressed resilient material, which when punctured or opened to the atmosphere expands to partially or completely fill the collapsed portion of the package. Atmospheric pressure acting upon the evacuated collapsed package maintains the compressed material in its reduced volume. When the package is punctured and the restraint of atmospheric pressure is removed, the resiliency of the material results in a volume increase. In one embodiment, a tear strip is provided along the length of the package to facilitate opening of the package and expansion of the material.

The package can be of a size equal to or greater than the expanded volume of the material. The expanded volume of material of course depends upon the amount of compression and the degree of resiliency of the particular material packaged. In the case of packaged rock wool insulation batts, it is preferred to use an oversized package so that the package edges provide a surface which can be stapled to the walls thus facilitating installation. Since the rock wool need not be removed from the package, personal discomfort and skin irritation resulting from the normal installation procedure for such materials are eliminated.

Further in accordance with the invention, there is provided a method of packaging resilient compressible material in air impervious thermoplastic film comprising positioning a length of the material between sheets of the film, with the film extending beyond the edges of the length of the material, hermetically sealing one end of the extending edges of film, simultaneously compressing and conveying the enclosed material while hermetically sealing the side edges of the film, and hermetically sealing the remaining open end of the sheets while the resilient material is being compressed. The method can be applied to material which is positioned in a folded film sheet, it being necessary to seal only one side, or it can be applied to material which is sandwiched between two sheets.

Referring now to the drawings wherein like reference numerals are used to denote like elements in the different figures, the invention will be described in detail. In FIGS. 1 and 2 the apparatus is mounted on a supporting frame work and a compressible material, inserted into a longitudinally folded sheet of thermoplastic film, is fed between continuous conveyor belts 11 and 12 which simultaneously compress the material to a desired thickness, evacuating air from the material, and convey it through the apparatus. The lower conveyor 11 is supported on rollers 13 and 14. The upper conveyor 12 is supported on rollers .16, 17 and 18. Roller 13 rotates on shaft 21. All shafts are supported on bearings (not shown) in framework 10. Roller 14 rotates on shaft 22 which is driven through a sprocket 23 and chain 24 by a suitable motor 26. The lower conveyor 11 is provided with a back up plate 27 supported on arms 28 of frame work 10 thus providing a back up member for the compressive force exerted on the material as it passes between the conveyors. If desired, belt tension can be utilized and plate 27 omitted.

The upper conveyor 12 is supported on a vertically adjustable frame member 31. Roller 16 rotates on a shaft 32 which is supported by member 31. Rollers 17 and 18 rotate about shafts 33 and 34 respectively which are also supported on member 31. Shaft 32 is driven by gear 36 which meshes with the train of gears 37, 38 and 39. All of the gears are contained in housing 41. Gear 39 is carried upon driven shaft 22 and meshes with a pivotally mounted gear 38 which in turn meshes with pivotally mounted gear 37 to drive gear 36. This gear train drives conveyor 12 at the same speed and in the same direction as conveyor -11 is driven by motor 26. The pivotal mounting of gears 37 and 38 allows the vertical adjustment of upper belt 12 as is described below.

A longitudinal plate 42 and an upwardly tilted plate 43 at the feed end are mounted between the arms of frame member 31 within conveyor 12 to provide the rigidity necessary to compress resilient material. When only a small amount of compression is desired, conveyor belts alone may be sufficiently rigid.

Frame member 31 is raised or lowered to give the desired thickness in the material being compressed. Frame member 31 is supported from framework 10 by worm and screw type actuators 46, 47, 48 and 49. A manually operated threaded shaft 51 and worm shaft 52 having a sprocket 53 drive a chain 54 which is positioned about sprocket 55 on actuator 47 and sprocket 56 on actuator 49. The worm components of actuators 47 and 49 rotate shafts 57 and 58 respectively which are coupled to the worm components of actuators 46 and 48 respectively. Thus the rotation of threaded shaft 51 raises or lowers all actuators an equal distance.

A side sealer 61, which will be described in detail with reference to FIG. 4, is carried on threaded shaft 51. In this particular embodiment, gearing (not shown) with the shaft is provided so that the sealing head is positioned at a point equidistant from the conveying surfaces of either conveyor, but the sealing head can be positioned 01f center if desired. The rotating members of sealer 61 are driven by belt 62 and pulley 63 which is mounted on shaft 21.

The plastic film is sealed to form the ends of the package by means of a heated sealing bar 71 which is mounted transversely over the feed end of the conveyors. The sealing bar contains an electrical heater, not shown. Sealing bar 71 is mounted on a cross member 72 which is slidably carried on guide rails 73 and 74. A safety switch 75 is mounted on member 72 extending downwardly and is connected to the apparatus to provide for shutdown if engaged by the operator. A pair of belts 76 and 77 are attached to cross member 72 and travel over pulleys 78 and 79. The belts are also attached to a sealing back up bar 81. Back up bar 81 is slidably carried on guide rails 73 and 74. An air cylinder 82 mounted on framework 10 is attached by shaft 83 to cross member 72.

Air pressure is supplied through line 84 at predetermined time intervals to drive the sealing bar downwardly and, through the pulley arrangement, raise the back up bar to meet the sealing bar.

As is shown in FIG. 2, sealing bar 71 is provided with a knife edge 86 in the center of the cross section and as shown in FIG. 1 the back up bar has a slot 87 to receive the knife edge. Thus as the sealing bar and its back up bar meet they form a seal at the trailing edge of the package being conveyed through the apparatus and a seal at the leading edge of the package next to be fed between the conveyors. The knife edge cuts the sealed film separating the packages into individual units.

FIG. 3 is a front view of the apparatus shown in FIGS. 1 and 2, illustrating an additional side sealer 66, belt 67 and pulley 68. These additional elements provide a modification which forms a compressed sealed package when the compressible material is fed to the apparatus sandwiched between two sheets of thermoplastic film. In both embodiments the package is fed with the leading edge sealed by bar 71 before entering between conveyors .11 and 12. As the package passes between the conveyors air is driven from the material and the package. Simultaneously the film extending beyond the side or sides of the conveyor is sealed. The trailing end of the film is sealed and excess film trimmed off and while the entire package is compressed between the conveyors, the last portions of the sides are sealed to prevent the re-entry of air.

Referring now to FIG. 4, a side sealer is shown in detail. The sealing head 90 and back up roll 91 are mounted on a channel-shaped frame 92 which is carried on threaded shaft 51. The frame rides on keyed guide rails 93 and 94 which fit through slotted holes in the frame to prevent rotation of the sealer.

Sealing head 90 contains electrical heater (not shown) which is connected to a power source by wiring. Roll 91 rotates on shaft 96 which is driven by belt 62 and pulley 97. A second pulley 98 mounted on shaft 96 carries a belt 99 which drives a pair of hip rolls 101 and 102. As the film 103 passes between sealing head 90 and roll 91 a hermetical seal 104 is formed. The sealed thermoplastic sheets are grasped between nip rolls 101 and 102 and tension is maintained to eliminate wrinkling of the seal as the film cools. The outer portion of roll .101 is bevelled to form a knife-edge for trimming excess film from the sealed edge. A heat sealing unit has been described, but equivalent elements, such as ultrasonic means, can be used.

In FIG. 5, hermetically sealed, partially collapsed, film package denoted generally by the numeral 110, is shown to contain the resilient material 111, in its compressed state. In this embodiment, the film is provided with a tear strip 112 over perforations in the film to facilitate opening the package to the atmosphere. The package, 110, has a volume at least equal to the volume to which the compressed material will expand when the package is punctured or opened to the atmosphere.

Any suitable thermoplastic film, such as polymeric materials, for example polyethylene or polypropylene, can be utilized to form the package of the invention. The film should be a sufficient thickness to withstand handling during shipping without puncture.

Reasonable modification and variation are within the scope of the invention which defines a novel packaging apparatus, a novel method of packaging, and a novel package.

That which is claimed is:

1. A method of packaging resilient compressible material in a compressed condition within an air impervious thermoplastic package, said package having a sealed, slotted opening so that when air is introduced therethrough the compressed material can fully expand within the volume of the package, said method comprising the steps of:

(1) positioning a length of said material between sheets of thermoplastic film extending beyond the edges of said material, at least one of said sheets having a sealed, slotted opening therein;

(2) hermetically heat sealing one end of the extending edges of said sheets thereby forming a first edge seal;

(3) compressing the film enclosed material of step (2);

(4) hermetically heat sealing side edges of said sheets, thereby forming at least one second edge seal; and

() hermetically heat sealing the remaining end of said sheets while said film enclosed material is being compressed thereby forming a last edge seal completing the formation of the hermetically sealed package, said seals being spaced a sufiicient distance from the compressible material that said package has at least sufficient internal volume to contain said compressible material in its expanded form when air is introduced through the slotted opening.

2. The method of claim 1 wherein said resilient com pressible material is packaged in a continuous manner by simultaneously compressing and conveying said material while forming said seals.

3. The method of claim 1 wherein said sheets of film prior to sealing are completely separate and said first edge seal, two separate side seals and said last edge seal are all formed by heat sealing, whereby said package comprises four interconnected heat seals.

4. The method of claim 1 wherein said resilient compressible material is packaged in a continuous manner by simultaneously compressing and conveying said material while forming said seals, said sheets of film prior to sealing being completely separate, and said first edge seal, two separate side edge seals and said last edge seal are all formed by heat sealing, whereby said package comprises four interconnected heat seals.

5. The method of claim 4 wherein said resilient compressible material is simultaneously compressed and conveyed between moving belts.

6. A method of packaging resilient compressible material in a compressed condition within an air impervious thermoplastic package, said package having a sealed tear strip so that when air is introduced therethrough the compressed material can fully expand within the volume of the package, said method comprising the steps of:

(1) positioning a length of said material between a folded sheet of thermoplastic film extending beyond the edges of said material, said film having a sealed, slotted opening therein;

(2) hermetically heat sealing one end of the extending edges of said sheets thereby forming a first edge seal;

(3) compressing the film enclosed material of step (2);

(4) hermetically heat sealing side edges of said sheets while under compression, thereby forming at least one second edge seal; and

(5) hermetically heat sealing the remaining end of said sheets while said film enclosed material is being compressed thereby forming a last edge seal completing the formation of the hermetically sealed package, said seals being spaced a sufiicient distance from the compressed material that said package has at least suflicient internal volume to contain said compressible material in its expanded form when air is introduced through said tear strip.

7. The method of claim 1 wherein said sealed, slotted opening is a tear strip.

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WAYNE A. MORSE, 111., Primary Examiner US. Cl. X.R. 

